The prevalence of waterborne or food-related diseases is on the rise, the Korea Centers for Disease Control and Prevention said Monday.

The center also called for extra care in personal hygiene as the weather grows hotter.

The number of such diseases reported between Jan. 1 and March 14 this year was 32, up from 24 cases a year earlier. The number of patients increased to 780, up from 492 over the same period.

Norovirus, which causes gastroenteritis, took the lion’s share with seven cases, followed by colliform bacillus, Bacillus cereus, Clostridium perfringens and Campylobacter jejuni.

The number of Norovirus cases has increased steadily over the past three years, the administration said.

“We asked cafeterias, canteens and other facilities that serve food to be on extra alert,” the KCDC said in a press release.

Authorities released a set of guidelines to help prevent the spread of the illnesses.

1. Always wash your hands with soap.

2. Thoroughly clean and cook food before eating and be mindful of drinking groundwater.

3. Always use safe water for everything, not only when drinking.

4. If a cook shows symptoms of diarrhea or vomiting, immediately relieve him or her from duty.

5. Always sterilize cooking utensils and areas before use.

6. Report to local public healthcare centers if a number of people complain of diarrhea or other stomach symptoms.